xref: /linux/drivers/tee/tstee/core.c (revision f898c16a0624e7f2dcb0b1cda6916c9be6489197)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2023, Arm Limited
4  */
5 
6 #include <linux/arm_ffa.h>
7 #include <linux/err.h>
8 #include <linux/errno.h>
9 #include <linux/kernel.h>
10 #include <linux/limits.h>
11 #include <linux/mm.h>
12 #include <linux/module.h>
13 #include <linux/scatterlist.h>
14 #include <linux/slab.h>
15 #include <linux/tee_core.h>
16 #include <linux/types.h>
17 #include <linux/uuid.h>
18 #include <linux/xarray.h>
19 #include "tstee_private.h"
20 
21 #define FFA_DIRECT_REQ_ARG_NUM 5
22 #define FFA_INVALID_MEM_HANDLE U64_MAX
23 
24 static void arg_list_to_ffa_data(const u32 *args,
25 				 struct ffa_send_direct_data *data)
26 {
27 	data->data0 = args[0];
28 	data->data1 = args[1];
29 	data->data2 = args[2];
30 	data->data3 = args[3];
31 	data->data4 = args[4];
32 }
33 
34 static void arg_list_from_ffa_data(const struct ffa_send_direct_data *data,
35 				   u32 *args)
36 {
37 	args[0] = lower_32_bits(data->data0);
38 	args[1] = lower_32_bits(data->data1);
39 	args[2] = lower_32_bits(data->data2);
40 	args[3] = lower_32_bits(data->data3);
41 	args[4] = lower_32_bits(data->data4);
42 }
43 
44 static void tstee_get_version(struct tee_device *teedev,
45 			      struct tee_ioctl_version_data *vers)
46 {
47 	struct tstee *tstee = tee_get_drvdata(teedev);
48 	struct tee_ioctl_version_data v = {
49 		.impl_id = TEE_IMPL_ID_TSTEE,
50 		/* FF-A endpoint ID only uses the lower 16 bits */
51 		.impl_caps = lower_16_bits(tstee->ffa_dev->vm_id),
52 		.gen_caps = 0,
53 	};
54 
55 	*vers = v;
56 }
57 
58 static int tstee_open(struct tee_context *ctx)
59 {
60 	struct ts_context_data *ctxdata;
61 
62 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
63 	if (!ctxdata)
64 		return -ENOMEM;
65 
66 	xa_init_flags(&ctxdata->sess_list, XA_FLAGS_ALLOC);
67 
68 	ctx->data = ctxdata;
69 
70 	return 0;
71 }
72 
73 static void tstee_release(struct tee_context *ctx)
74 {
75 	struct ts_context_data *ctxdata = ctx->data;
76 	struct ts_session *sess;
77 	unsigned long idx;
78 
79 	if (!ctxdata)
80 		return;
81 
82 	xa_for_each(&ctxdata->sess_list, idx, sess) {
83 		xa_erase(&ctxdata->sess_list, idx);
84 		kfree(sess);
85 	}
86 
87 	xa_destroy(&ctxdata->sess_list);
88 
89 	kfree(ctxdata);
90 	ctx->data = NULL;
91 }
92 
93 static int tstee_open_session(struct tee_context *ctx,
94 			      struct tee_ioctl_open_session_arg *arg,
95 			      struct tee_param *param __always_unused)
96 {
97 	struct tstee *tstee = tee_get_drvdata(ctx->teedev);
98 	struct ffa_device *ffa_dev = tstee->ffa_dev;
99 	struct ts_context_data *ctxdata = ctx->data;
100 	struct ffa_send_direct_data ffa_data;
101 	struct ts_session *sess = NULL;
102 	u32 ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
103 	u32 sess_id;
104 	int rc;
105 
106 	ffa_args[TS_RPC_CTRL_REG] =
107 		TS_RPC_CTRL_PACK_IFACE_OPCODE(TS_RPC_MGMT_IFACE_ID,
108 					      TS_RPC_OP_SERVICE_INFO);
109 
110 	memcpy(ffa_args + TS_RPC_SERVICE_INFO_UUID0, arg->uuid, UUID_SIZE);
111 
112 	arg_list_to_ffa_data(ffa_args, &ffa_data);
113 	rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data);
114 	if (rc)
115 		return rc;
116 
117 	arg_list_from_ffa_data(&ffa_data, ffa_args);
118 
119 	if (ffa_args[TS_RPC_SERVICE_INFO_RPC_STATUS] != TS_RPC_OK)
120 		return -ENODEV;
121 
122 	if (ffa_args[TS_RPC_SERVICE_INFO_IFACE] > U8_MAX)
123 		return -EINVAL;
124 
125 	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
126 	if (!sess)
127 		return -ENOMEM;
128 
129 	sess->iface_id = ffa_args[TS_RPC_SERVICE_INFO_IFACE];
130 
131 	rc = xa_alloc(&ctxdata->sess_list, &sess_id, sess, xa_limit_32b,
132 		      GFP_KERNEL);
133 	if (rc) {
134 		kfree(sess);
135 		return rc;
136 	}
137 
138 	arg->session = sess_id;
139 	arg->ret = 0;
140 
141 	return 0;
142 }
143 
144 static int tstee_close_session(struct tee_context *ctx, u32 session)
145 {
146 	struct ts_context_data *ctxdata = ctx->data;
147 	struct ts_session *sess;
148 
149 	/* Calls xa_lock() internally */
150 	sess = xa_erase(&ctxdata->sess_list, session);
151 	if (!sess)
152 		return -EINVAL;
153 
154 	kfree(sess);
155 
156 	return 0;
157 }
158 
159 static int tstee_invoke_func(struct tee_context *ctx,
160 			     struct tee_ioctl_invoke_arg *arg,
161 			     struct tee_param *param)
162 {
163 	struct tstee *tstee = tee_get_drvdata(ctx->teedev);
164 	struct ffa_device *ffa_dev = tstee->ffa_dev;
165 	struct ts_context_data *ctxdata = ctx->data;
166 	struct ffa_send_direct_data ffa_data;
167 	struct tee_shm *shm = NULL;
168 	struct ts_session *sess;
169 	u32 req_len, ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
170 	int shm_id, rc;
171 	u8 iface_id;
172 	u64 handle;
173 	u16 opcode;
174 
175 	xa_lock(&ctxdata->sess_list);
176 	sess = xa_load(&ctxdata->sess_list, arg->session);
177 
178 	/*
179 	 * Do this while holding the lock to make sure that the session wasn't
180 	 * closed meanwhile
181 	 */
182 	if (sess)
183 		iface_id = sess->iface_id;
184 
185 	xa_unlock(&ctxdata->sess_list);
186 	if (!sess)
187 		return -EINVAL;
188 
189 	opcode = lower_16_bits(arg->func);
190 	shm_id = lower_32_bits(param[0].u.value.a);
191 	req_len = lower_32_bits(param[0].u.value.b);
192 
193 	if (shm_id != 0) {
194 		shm = tee_shm_get_from_id(ctx, shm_id);
195 		if (IS_ERR(shm))
196 			return PTR_ERR(shm);
197 
198 		if (shm->size < req_len) {
199 			dev_err(&ffa_dev->dev,
200 				"request doesn't fit into shared memory buffer\n");
201 			rc = -EINVAL;
202 			goto out;
203 		}
204 
205 		handle = shm->sec_world_id;
206 	} else {
207 		handle = FFA_INVALID_MEM_HANDLE;
208 	}
209 
210 	ffa_args[TS_RPC_CTRL_REG] = TS_RPC_CTRL_PACK_IFACE_OPCODE(iface_id,
211 								  opcode);
212 	ffa_args[TS_RPC_SERVICE_MEM_HANDLE_LSW] = lower_32_bits(handle);
213 	ffa_args[TS_RPC_SERVICE_MEM_HANDLE_MSW] = upper_32_bits(handle);
214 	ffa_args[TS_RPC_SERVICE_REQ_LEN] = req_len;
215 	ffa_args[TS_RPC_SERVICE_CLIENT_ID] = 0;
216 
217 	arg_list_to_ffa_data(ffa_args, &ffa_data);
218 	rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data);
219 	if (rc)
220 		goto out;
221 
222 	arg_list_from_ffa_data(&ffa_data, ffa_args);
223 
224 	if (ffa_args[TS_RPC_SERVICE_RPC_STATUS] != TS_RPC_OK) {
225 		dev_err(&ffa_dev->dev, "invoke_func rpc status: %d\n",
226 			ffa_args[TS_RPC_SERVICE_RPC_STATUS]);
227 		rc = -EINVAL;
228 		goto out;
229 	}
230 
231 	arg->ret = ffa_args[TS_RPC_SERVICE_STATUS];
232 	if (shm && shm->size >= ffa_args[TS_RPC_SERVICE_RESP_LEN])
233 		param[0].u.value.a = ffa_args[TS_RPC_SERVICE_RESP_LEN];
234 
235 out:
236 	if (shm)
237 		tee_shm_put(shm);
238 
239 	return rc;
240 }
241 
242 static int tstee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
243 			      struct page **pages, size_t num_pages,
244 			      unsigned long start __always_unused)
245 {
246 	struct tstee *tstee = tee_get_drvdata(ctx->teedev);
247 	struct ffa_device *ffa_dev = tstee->ffa_dev;
248 	struct ffa_mem_region_attributes mem_attr = {
249 		.receiver = tstee->ffa_dev->vm_id,
250 		.attrs = FFA_MEM_RW,
251 		.flag = 0,
252 	};
253 	struct ffa_mem_ops_args mem_args = {
254 		.attrs = &mem_attr,
255 		.use_txbuf = true,
256 		.nattrs = 1,
257 		.flags = 0,
258 	};
259 	struct ffa_send_direct_data ffa_data;
260 	struct sg_table sgt;
261 	u32 ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
262 	int rc;
263 
264 	rc = sg_alloc_table_from_pages(&sgt, pages, num_pages, 0,
265 				       num_pages * PAGE_SIZE, GFP_KERNEL);
266 	if (rc)
267 		return rc;
268 
269 	mem_args.sg = sgt.sgl;
270 	rc = ffa_dev->ops->mem_ops->memory_share(&mem_args);
271 	sg_free_table(&sgt);
272 	if (rc)
273 		return rc;
274 
275 	shm->sec_world_id = mem_args.g_handle;
276 
277 	ffa_args[TS_RPC_CTRL_REG] =
278 			TS_RPC_CTRL_PACK_IFACE_OPCODE(TS_RPC_MGMT_IFACE_ID,
279 						      TS_RPC_OP_RETRIEVE_MEM);
280 	ffa_args[TS_RPC_RETRIEVE_MEM_HANDLE_LSW] =
281 			lower_32_bits(shm->sec_world_id);
282 	ffa_args[TS_RPC_RETRIEVE_MEM_HANDLE_MSW] =
283 			upper_32_bits(shm->sec_world_id);
284 	ffa_args[TS_RPC_RETRIEVE_MEM_TAG_LSW] = 0;
285 	ffa_args[TS_RPC_RETRIEVE_MEM_TAG_MSW] = 0;
286 
287 	arg_list_to_ffa_data(ffa_args, &ffa_data);
288 	rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data);
289 	if (rc) {
290 		(void)ffa_dev->ops->mem_ops->memory_reclaim(shm->sec_world_id,
291 							    0);
292 		return rc;
293 	}
294 
295 	arg_list_from_ffa_data(&ffa_data, ffa_args);
296 
297 	if (ffa_args[TS_RPC_RETRIEVE_MEM_RPC_STATUS] != TS_RPC_OK) {
298 		dev_err(&ffa_dev->dev, "shm_register rpc status: %d\n",
299 			ffa_args[TS_RPC_RETRIEVE_MEM_RPC_STATUS]);
300 		ffa_dev->ops->mem_ops->memory_reclaim(shm->sec_world_id, 0);
301 		return -EINVAL;
302 	}
303 
304 	return 0;
305 }
306 
307 static int tstee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
308 {
309 	struct tstee *tstee = tee_get_drvdata(ctx->teedev);
310 	struct ffa_device *ffa_dev = tstee->ffa_dev;
311 	struct ffa_send_direct_data ffa_data;
312 	u32 ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
313 	int rc;
314 
315 	ffa_args[TS_RPC_CTRL_REG] =
316 			TS_RPC_CTRL_PACK_IFACE_OPCODE(TS_RPC_MGMT_IFACE_ID,
317 						      TS_RPC_OP_RELINQ_MEM);
318 	ffa_args[TS_RPC_RELINQ_MEM_HANDLE_LSW] =
319 			lower_32_bits(shm->sec_world_id);
320 	ffa_args[TS_RPC_RELINQ_MEM_HANDLE_MSW] =
321 			upper_32_bits(shm->sec_world_id);
322 
323 	arg_list_to_ffa_data(ffa_args, &ffa_data);
324 	rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data);
325 	if (rc)
326 		return rc;
327 	arg_list_from_ffa_data(&ffa_data, ffa_args);
328 
329 	if (ffa_args[TS_RPC_RELINQ_MEM_RPC_STATUS] != TS_RPC_OK) {
330 		dev_err(&ffa_dev->dev, "shm_unregister rpc status: %d\n",
331 			ffa_args[TS_RPC_RELINQ_MEM_RPC_STATUS]);
332 		return -EINVAL;
333 	}
334 
335 	rc = ffa_dev->ops->mem_ops->memory_reclaim(shm->sec_world_id, 0);
336 
337 	return rc;
338 }
339 
340 static const struct tee_driver_ops tstee_ops = {
341 	.get_version = tstee_get_version,
342 	.open = tstee_open,
343 	.release = tstee_release,
344 	.open_session = tstee_open_session,
345 	.close_session = tstee_close_session,
346 	.invoke_func = tstee_invoke_func,
347 };
348 
349 static const struct tee_desc tstee_desc = {
350 	.name = "tstee-clnt",
351 	.ops = &tstee_ops,
352 	.owner = THIS_MODULE,
353 };
354 
355 static int pool_op_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
356 			 size_t size, size_t align)
357 {
358 	return tee_dyn_shm_alloc_helper(shm, size, align, tstee_shm_register);
359 }
360 
361 static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm)
362 {
363 	tee_dyn_shm_free_helper(shm, tstee_shm_unregister);
364 }
365 
366 static void pool_op_destroy_pool(struct tee_shm_pool *pool)
367 {
368 	kfree(pool);
369 }
370 
371 static const struct tee_shm_pool_ops pool_ops = {
372 	.alloc = pool_op_alloc,
373 	.free = pool_op_free,
374 	.destroy_pool = pool_op_destroy_pool,
375 };
376 
377 static struct tee_shm_pool *tstee_create_shm_pool(void)
378 {
379 	struct tee_shm_pool *pool = kzalloc(sizeof(*pool), GFP_KERNEL);
380 
381 	if (!pool)
382 		return ERR_PTR(-ENOMEM);
383 
384 	pool->ops = &pool_ops;
385 
386 	return pool;
387 }
388 
389 static bool tstee_check_rpc_compatible(struct ffa_device *ffa_dev)
390 {
391 	struct ffa_send_direct_data ffa_data;
392 	u32 ffa_args[FFA_DIRECT_REQ_ARG_NUM] = {};
393 
394 	ffa_args[TS_RPC_CTRL_REG] =
395 			TS_RPC_CTRL_PACK_IFACE_OPCODE(TS_RPC_MGMT_IFACE_ID,
396 						      TS_RPC_OP_GET_VERSION);
397 
398 	arg_list_to_ffa_data(ffa_args, &ffa_data);
399 	if (ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &ffa_data))
400 		return false;
401 
402 	arg_list_from_ffa_data(&ffa_data, ffa_args);
403 
404 	return ffa_args[TS_RPC_GET_VERSION_RESP] == TS_RPC_PROTOCOL_VERSION;
405 }
406 
407 static int tstee_probe(struct ffa_device *ffa_dev)
408 {
409 	struct tstee *tstee;
410 	int rc;
411 
412 	ffa_dev->ops->msg_ops->mode_32bit_set(ffa_dev);
413 
414 	if (!tstee_check_rpc_compatible(ffa_dev))
415 		return -EINVAL;
416 
417 	tstee = kzalloc(sizeof(*tstee), GFP_KERNEL);
418 	if (!tstee)
419 		return -ENOMEM;
420 
421 	tstee->ffa_dev = ffa_dev;
422 
423 	tstee->pool = tstee_create_shm_pool();
424 	if (IS_ERR(tstee->pool)) {
425 		rc = PTR_ERR(tstee->pool);
426 		tstee->pool = NULL;
427 		goto err_free_tstee;
428 	}
429 
430 	tstee->teedev = tee_device_alloc(&tstee_desc, NULL, tstee->pool, tstee);
431 	if (IS_ERR(tstee->teedev)) {
432 		rc = PTR_ERR(tstee->teedev);
433 		tstee->teedev = NULL;
434 		goto err_free_pool;
435 	}
436 
437 	rc = tee_device_register(tstee->teedev);
438 	if (rc)
439 		goto err_unreg_teedev;
440 
441 	ffa_dev_set_drvdata(ffa_dev, tstee);
442 
443 	return 0;
444 
445 err_unreg_teedev:
446 	tee_device_unregister(tstee->teedev);
447 err_free_pool:
448 	tee_shm_pool_free(tstee->pool);
449 err_free_tstee:
450 	kfree(tstee);
451 	return rc;
452 }
453 
454 static void tstee_remove(struct ffa_device *ffa_dev)
455 {
456 	struct tstee *tstee = ffa_dev->dev.driver_data;
457 
458 	tee_device_unregister(tstee->teedev);
459 	tee_shm_pool_free(tstee->pool);
460 	kfree(tstee);
461 }
462 
463 static const struct ffa_device_id tstee_device_ids[] = {
464 	/* TS RPC protocol UUID: bdcd76d7-825e-4751-963b-86d4f84943ac */
465 	{ TS_RPC_UUID },
466 	{}
467 };
468 
469 static struct ffa_driver tstee_driver = {
470 	.name = "arm_tstee",
471 	.probe = tstee_probe,
472 	.remove = tstee_remove,
473 	.id_table = tstee_device_ids,
474 };
475 
476 module_ffa_driver(tstee_driver);
477 
478 MODULE_AUTHOR("Balint Dobszay <balint.dobszay@arm.com>");
479 MODULE_DESCRIPTION("Arm Trusted Services TEE driver");
480 MODULE_LICENSE("GPL");
481